If you want to issue multiple commands with one call to pt.command[], the second argument will need to be a list of strings. Placing a comma between strings joins them together into a list, even if they're spread across multiple lines:
pt.command[deck "!show NAME1 EMOTE customPOS1", "!show NAME2 EMOTE customPOS2" ]
The above is equivalent to:
pt.command[deck ("!show NAME1 EMOTE customPOS1","!show NAME2 EMOTE customPOS2")]